1. Field of The Invention
The present invention relates to a video compact disc having caption data recorded thereon and reproducing method and apparatus thereof, and more particularly to a compact disc having caption data recorded on a control data area thereof (i.e., compact disc graphics data area) and to a reproducing method and an apparatus for performing a selective playback or on/off driving of the caption data recorded on the video compact disc.
2. Description of the Prior Art As is generally known, a compact disc graphics (hereinafter referred to as "CDG" for short) disc having graphics data recorded thereon has been developed from a compact disc (hereinafter referred to as "CD"), which is well known as an information recording medium on which a large quantity of audio signals of high fidelity is recorded, and has been put to practical use. Generally, the CDG disc includes a subcode consisting of a P channel for displaying whether or not an audio signal is recorded, a Q channel assigned to the audio signal, and R channel-W channel allotted for recording the graphics data, so that a graphic video signal related to the audio signal is reproduced during the playback operation of the audio signal.
Recently, a so-called video compact disc (hereinafter referred to as "VCD"), on which full motion video information is, recorded, has been put to practical use. In the VCD, a full motion picture and an audio signal are recorded in a data compression system by means of a moving picture experts group (hereinafter referred to as "MPEG" for short) algorithm, and the compressed data is decoded to reproduce the original video signal and audio signal. Therefore, since the data of a full motion picture can be recorded on/reproduced from the VCD, a karaoke music program (hereinafter referred to as "video-song program") or a movie program can be recorded thereon. The VCD includes a user data (video program data) area, an error correction code recording area and a control data area having a subcode recorded thereon, which has the same pattern as the CDG disc. By this area configuration, when recording a video-song program or a movie program, word data of a video-song or caption data such as the lines of the movie can be recorded on the CDG. However, despite assigning the control data recording area having the same data structure as that of the CDG disc, when program data (i.e., video data) is recorded on the VCD, instead of using the control data recording area, the word data of a video-song or the caption data of a movie program are generally recorded on the user data area in the state where the data compression processing of the word data of a video-song or the caption data of a movie program has performed together with the program data by means of the MPEG algorithm.
One example of a method and apparatus for recording and reproducing picture information and recording medium is disclosed as follows in U.S. Pat. No. 5,282,186, issued to Yoshio et al. Here, in addition to a coded information signal, subcodes, together with identification codes for identifying the coding system of the subcodes, are recorded in a first recording area of a recording medium, and the identification codes and content discrimination codes, for indicating contents of information included in the subcode using the coding system indicated by the identification code, are recorded in a second recording area of the recording medium. It is further characterized in that the identification code and the content discrimination information recorded in the second recording area are displayed at the time of playback of the recording medium.
One example of a method and apparatus for storing MIDI (musical instrument digital interface) information in subcode packs is disclosed as follows in U.S. Pat. No. 4,942,551. The apparatus and method encodes data in a MIDI format on an audio compact disc, without affecting the digitized sound stored in the main channel by utilizing what is known as the subcode channel of the compact disc, which is reserved for information other than digitized compact disc audio data. The patent is directed to a technique for converting the MIDI information generated by a MIDI source (for example, a keyboard or a sequencer) into subcode data, which may be recorded on a transportable floppy diskettes or other transportable media for subsequent conversion to signals which are inputted to a compact disc encoder which places the MIDI information into the subcode channel.
In the VCD of the above structure and the reproducing apparatus thereof having the caption data, which is recorded thereon, because the word data of the video-song information or the caption data of the movie program recorded on the VCD are recorded in the state where either the word data of the video-song information or the caption data of the movie program are superimposed on the original video signal, only word data or caption data of a single kind can be recorded. Furthermore, since either the word data or the caption data is recorded together with the video program information in a mixed structure, it is difficult to perform selective on/off playback operation of either the word data or the caption dam.